Dialkyl silane derivative of ricinoleic acid ester



Patented Feb. 7, 1950 DIALKYL SILANE DERIVATIVE OF RICINOLEIC ACID ESTER Robert Edward Christ, Elizabeth, N. 1., minor to U. S. Industrial Chemicals, Inc.,

New York,

N. Y., a corporation of Delaware No Drawing. Application November 27, 1948, Serial No. 62,430

3 Claims.

This invention relates to new compositions of matter which are useful plasticizers for nitrocellulose.

A great many plasticizers 'f'or nitrocellulose are known. There is a need in the art, however, for additional plasticizers which, when combined with nitrocellulose, will yield fllms of low elastic modulus and high folding flexibility. In addition, there is 'a need for plasticizers which with nitrocellulose produce films of increased useful working temperature range and increased flexibility at low temperatures.

It is the object of the present invention to provide improved plasticizers for nitrocellulose meeting the aforementioned requirements.

The aforementioned and other objects are accomplished in accordance with the present invention bp providing a composition which consists essentially of a compound or compounds having the generic formula in which Rand R are alkyl radicals having from one to six carbon atoms. Preferably both R and R are normal alkyl radicals.

The following example illustrates in detail the preparation of a specific composition falling within the scope of the present invention, and is to be considered not limitative thereof.

Example A mixture which consisted essentially of butyl ricinoleate was prepared .by the alcohoiysis of castor oil with butyl alcohol. 354.6 gins. of this material and 88' ms. of diethyl diethoxy silane were charged into a three-necked flask fitted with a thermometer, stirrer, reflux take-oil head, a vapor thermometer and a reflux condenser. The temperature of the reaction mixture was then raised to about 118 C., at which point the vapor temperature was about 83 C. due to the refluxing of ethyl alcohol resulting from the reaction. The refluxing was maintained for about two hours, after which the ethyl alcohol was gradually removed by means of the take-01f head. When the temperature in the flask reached about 200 C..

2 the heating was stopped and the batch was permitted to cool. The remainder of the ethyl alcohol was then removed at an absolute pressure of about 25 mm. of mercury.

This procedure yielded 374 guns. of a composition which consisted essentially of the compound The composition prepared as described had a Gardner-Holdt viscosity of A1, a kinematic viscosity at 210 F. of 11.01 centistokes, a kinematic viscosity at F. of 33.4 centistokes, a viscosi y index of 177 and a refractive index of 1.461.

Since castor oil is widely used in the art for plastic-12mg nitrocellulose films, a comparison was made between castor oil and the above composition when employed for that purpose. In making this comparison, nitrocellulose solutions were prepared according to the formulations listed in the table below.

Nitrocellulose, gm 104.3 104.3 AA Castor Oil, gm 156.5

Composition of Example, gm 156.5 Alcohol 23, ml 101.7 101.7 Toluene, m1 400.1 400.1 Butyl acetate, ml 237.4 237.4

The nitrocellulose used was a commercial grade. having a viscosity or 33 seconds and a. nitrogen content of 11.8-12.2%, and the alcohol 23 contained 100 volumes of 200 proof ethyl alcohol per 0.5 volume of benzene.

A master batch oi solution was first prepared by wetting the nitrocellulose with the non-solvents (Alcohol 23 and toluene), and then adding the butyl acetate. This mixture was then tumbled until the solution was completely homogeneous, after which the solution was filtered through a mat of glass wool, using pressure. The nitrocellulose solution and the plasticizer were thereafter weighed out in the correct proportions, and the mixture was again tumbled until it was completely homogeneous. Films were prepared by spreading the solution on glass by means Of a doctor blade. The films thus laid accuses down were conditioned at room temperature for 2 hours, followed by a further conditioning of 24 hours at 50 C. under forced air drying. The final thickness oi the films was approximately cool".

The properties of the cm compared as is shown in the tollowing table:

Nitrocellulose (33 sec.) 1%.3 104.8 AA cwtor oil i565 m @omposition oi Example 156s Elastic modulus, 50% stretch" 13ml 1,590 Elongation at break, per cent... 91 98 Tensile strength, lbs/in. 2,560 2,514]? spew point, F 3165 llill Cold crack, "136 +2 ll6 m Flex Folds, at 0 o coo 23sec Hardness, Sword rocker 6 8 In the table above, the spew point is the lowest temperature at which exudation of the plastlclzer takes place on heating the film for one hour in an oven with air circulation. The exudation was tested for by quickly rubbing the film on. a clean slate, which was also kept in the oven. Au oily streak on the slate indicated spewing.

The cold crack point is essentially the temperature at which the film becomes brittle enough to break under a sudden shock or strain. The apparatus employed in determining the cold crack point consisted of a standard test tube holder with a sliding lock to hold the jaws of the holder open. The film was tested by placing it "in the open jaws of the holder, immersing the entire lower half of the apparatus in a Dewar flask to bring the film to the desired temperattue, and then releasing the laws by pulling up on the sliding look after temperature equilibrium had been reached in the film. This procedure impa ed simultaneously a sharp crease and a shattering blow to the film. This procedure was repeated at 5 C. at intervals until the film cracked under the impact of the laws.

The one Flex Folds test involves holding a strip of film under a definite tension and bending it rapidly around a curved surface until failure occurs. This is a useful test for all types of papers, films, or packaging materials which are creased, bent sharply, or handled to a considerable extent during their useful life.

From the preceding table it is apparent that the film plastlcized with the composition pre pared as above described had a much lower elastic modulus than that plastlcized with castor 011. As a result, the former film was more useful in the coating of fabrics, since a film having a low elastic modulus produces a. soft feeling and good drape in coated fabrics, in contrast to a hard feeling and boardiness produced by films of high elastic modulus.

It is also apparent from the foregoing .table that the composition prepared as described has a wider useful range (the spread between the cold crack point and the spew point), than castor oil, the ranges being, respectively, 264 F. and 163 F.

A variety of modifications may be made in the specific procedure of the example to provide additional composltions falling within the scope d of the present invention. 'lhus. such compounds may also be prepared by reacting methyl riclnoleate and dimethyl dlethozy silane with removal of ethyl alcohol. ethyl ricinoleatc and dimetbyl diethoxy silane with removal of ethyl alcohol. butyl ricinoleate and dl-isopropyl dimethoxy silane with removal of methyl alcohol, isobutyi rlclnoieate and di-n-butyl dlethoxy .silane with removal of ethyl alcohol, n-amyl ricinoleate and di-n-propyl diethoxy silane with removal of ethyl alcohol, n-hexyl riciuoleate and di-n-propyl di-\ .ethoxy sil-ane with removal of ethyl alcohol, etc. 1

In addition, compositions falling within the scope of this invention may also be prepared by reacting a mixture of any of the aforementioned rlcinoleates with a mixture of any of the aforementioned silanes. Furthermore. the R's of the generic formula need not be the same alkyi radical, ethyl n-propyl diethoxy silane, ethyl isobutyl dicthoxy silane, etc. also being useful in preparing the compositions described herein. The reaction mixture should contain substantlally two moles of ricinoleate ester per mole of silane.

The compositions of the present invention supply a need in the art for additional plasticizers for nitrocellulose films, and are useful for that purpose in that the films thus prepared are characterized by a low elastic modulus, a wide workinc range, by high folding flexibility, and by other advantageous properties.

I claim:

1. A composition which is a useful plasticizer for nitrocellulose, the said composition consisting essentially of a compound having the generic formula in which R and R are alkyl radicals having from one to six carbon atoms.

2. The composition of claim 1 in which R and R are normal allsyl radicals.

3. The composition of claim 2 in which R is the ethyl radical and R the n-butyl radical.

' ROBERT EDWARD CHRIST.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,918,338 Kaufman July 18, 1933 2,270,352 Sowa Jan. 20, 1942 FOREIGN PATENTS Number Country Date 625,61"! Germany May 24, 1938 OTHER REFERENCES Kreshkov, Jour. Gen. Chem. (U. S. S. R.), Vol l7 (1947) P ses 81-863.

Certificate of Correction Patent No. 2,496,335 February 7, 1950 ROBERT EDWARD CHRIST It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 1, line 18, for hp read by; column 3, line 64, for 264 F. read 246 F.;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent ()fiice.

Signed and sealed this 23rd day of May, A. D. 1950..

THOMAS F. MURPHY,

Assistant Uonmiaaa'om of Patenfh. 

1. A COMPOSITION WHICH IS A USEFUL PLASTICIZER FOR NITROCELLULOSE, THE SAID COMPOSITION CONSISTING ESSENTIALLY OF A COMPOUND HAVING THE GENERIC FORMULA 